Objective To enhance the level and ability of measuring pesticide residues in raw milk and find out the primary factors of affecting measurement uncertainty.Methods The mathematic model of measurement was established in order to evaluate measurement uncertainty of organophosphorus pesticide residues in raw milk with gas chromatography.Results The standard measurement uncertainty of organophosphorus pesticide residues in raw milk made up of weighing,sampling and diluting procedures,standard matter,sample volume,instrument calibration.The calculating formula of expanded measurement uncertainty was U=k?CX?urel(tptal).The expression of measurement result was C=CX?U.Volume of 6 kinds of organophosphorus pesticides residues were 0.4?0.050,0.4?0.029,0.4?0.027,0.4?0.029,0.4?0.057,0.4?0.034(mg/kg) respectively in raw milk which the standard matter of pesticide was added in.Conclusion From the evaluation of measurement uncertainty of pesticide residues in raw milk with gas chromatography,we can see that the measurement uncertainty is composed of many factors,which commonly comes from random variable and fuzzification,and can be assessed by statistic distribution and standard deviation.

Objective To determine the power-time-ablation scope correlogram of a water-cooled single needle electrode radiofrequency (RF) ablation system and to establish a theoretical basis for its practical application.Methods RF ablations were performed using a water-cooled single needle electrode radiofrequency ablation system developed by the authors using fresh ox liver as well as liver and muscles of healthy adult New Zealand white rabbits.The temperature of the ablation area was monitored using a multichannel thermometric system.The maximum ablation scope was determined by detecting the rim at which the temperature was no less than 50 °C.The specific absorption rate (SAR) of the isolated liver tissue was calculated.Results In the treatment voltage range of 100-130V,the process was smooth and steady.No impedance variation was obvious.The maximum diameter of a single ablation was 51 cm.With the treatment voltage at 140-170 V,a larger ablation area could be reached in less time,but eventually the impedance began to increase while the ablation area was no longer expanded.When the treatment voltage reached the range of 180-200 V the impedance almost always increased rapidly out of limits,and the treatment system stopped automatically.The measured SAR value was consistent with the theoretical value.Pathology confirmed that both liver tissue and muscle tissue manifested typical coagulative necrosis.Conclusions The power amplifier,cooling,thermometric and control sections of the RF ablation system worked stably,and the practical ablation effect met the design and clinical treatment requirements.

Objective:To investigate the value of atropine administration before tracheal intubation under general anesthesia in the elderly patients undergoing endobronchial ultrasound-guided transbronchial needle aspiration(EBUS-TBNA)biopsy.Methods:This was a case-control study.A total of 87 elderly hospitalized patients receiving chest enhanced CT test suggesting the risk of lung cancer with enlargement of mediastinal lymph nodes in 7 regions were scheduled to undergo endobronchial ultrasound-guided transbronchial needle aspiration(EBUS-TBNA)biopsy under general anesthesia.The patients were randomly divided into two groups by flipping a coin: the atropine group(n=40)and the control group(n=47). The indicators for evaluating the application values of atropine included preoperative, intra-operative and postoperative systolic blood pressure(SBP), diastolic blood pressure(DBP), heart rate, oropharyngeal and airway secretion volume, oxygen saturation, operation time, positive diagnosis rate and postoperative adverse reactions.Results:SBP and DBP were lower in the atropine group than in the control group before endotracheal intubation(131.7±15.3 mmHg vs.140.7±13.7 mmHg, 79.1±7.6 mmHg vs.85.6±7.4 mmHg, t=2.885 and 4.061, P<0.05). There was no significant difference in SBP and DBP 10 min after endoscopic operation and 10 min after tracheal extubation between the atropine group versus the control group(SBP: 109.1±11.2 mmHg vs.105.0±12.2 mmHg, 136.9±23.0 mmHg vs.129.9±11.2 mmHg, DBP: 66.9±7.5 mmHg vs.68.0±8.3 mmHg, 77.6±10.9 mmHg vs.78.5±6.4 mmHg, t=-1.617, 0.687, -1.751 and 0.448, P>0.05). There was no significant difference in HR between the two groups before endotracheal intubation( t=1.416, P>0.05), while HR was higher in the atropine group than in the control group 10 min after endoscopic operation and 10 min after tracheal extubation( t=-3.323 and -2.181, P<0.01 and P<0.05). The change rates of SBP and DBP were lower in the atropine group than in the control group 10 min after endoscopic operation and 10 min after tracheal extubation( t=7.947, -6.962, -3.187 and -3.232, P<0.01). The change rate of HR was lower in the atropine group 10 min after endoscopic operation and was higher 10 min after tracheal extubation than in the control group( t=-6.467 and -4.131, P<0.01). There were significant differences in the volume of oropharyngeal and airway secretions and fingertip oxygen saturation between the two groups before endotracheal intubation and 10 min after tracheal extubation( t=-2.334, 2.759, -3.314 and -2.767, P<0.01). The endoscopic operation time was less in the atropine group than in the control group with no statistically significant difference[(25.9±5.7)min vs.(26.4±4.7)min, t=0.391, P>0.05]. There was no significant difference in postoperative adverse reactions between the atropine group versus the control group(34 patients or 85.0% vs.43 patients or 91.5%, χ2=1.247, P>0.05). Conclusions:The application of atropine before tracheal intubation under general anesthesia is beneficial to stabilizing the intraoperative blood pressure and heart rate, and can reduce the production of postoperative oropharyngeal and airway secretions in elderly patients undergoing endobronchial ultrasound-guided transbronchial needle aspiration biopsy.

BACKGROUND:Due to limitations of the physicochemical properties of soft denture liner material itself, whisker has been added in the soft lining material in recent years, so as to enhance its mechanical properties. OBJECTIVE:To investigate the effect of different additive amount of anhydrous calcium sulfate whisker on the mechanical function of self-curing soft denture liner. METHODS: There were six groups in this experiment. Anhydrous calcium sulfate whisker at the mass fraction of 0 (control), 1%, 2%, 3%, 4%, 5% was respectively added into self-curing soft liner materials, 10 test specimens in each group, a total of 60 test specimens. The shear bond strength, Shore hardness and tensile strength were detected. RESULTS AND CONCLUSION: With the increasing amount of the anhydrous calcium sulfate whisker, the Shore hardness of the soft lining material was increased continuously, and the tensile strength was increased firstly and then reduced. When 3% anhydrous calcium sulfate whisker was added, the bond strength and tensile strength of soft lining material reached the peak. Taken together, the mechanical properties of the soft lining materials became perfect when 3% anhydrous calcium sulfate whisker was added. These results demonstrate that anhydrous calcium sulfate whisker may affect the mechanical properties of self-curing soft liner.

Objective:To analyze survival in patients with advanced oral cancer from prospective clinical trials. Methods:From 2008 to 2010, 256 patients with oral cancer at clinical stage III/IVA were randomly categorized into two groups. Patients in the experi-mental group received neo-adjuvant chemotherapy, surgery, and post-operative radiation, and patients in the control group underwent surgery and post-operative radiation. All patients were routinely followed-up after treatments. Survival was analyzed using Kaplan–Meier method and log-rank test, and differences were considered statistically significant at P value lower than 0.05. Results: Each group was composed of 128 patients. With the median follow-up period of 60 months, the 5-year overall survival rate was 61.7%and the disease-free survival rate was 53.9%. The overall survival rate (P=0.350) and the disease-free survival rate (P=0.160) were not sig-nificantly different between the experimental and control groups. Patients with positive pathological response to neo-adjuvant chemo-therapy exhibited significantly improved overall survival (P＜0.05). Conclusion:Radical surgery should be emphasized to improve the prognosis of oral cancer. Functional reconstruction could also improve the quality of life and survival of patients. Despite that neo-adju-vant chemotherapy could not improve the survival of patients with advanced oral cancer in entirety, it could benefit patients exhibiting positive treatment responses.

The biological clock(also known as the circadian rhythm)is the fundamental reliance for all organisms on Earth to adapt and survive in the Earth's rotation environment.Circadian rhythm is the most basic regulatory mechanism of life activities,and plays a key role in maintaining normal physiological and biochemical homeostasis,disease occurrence and treatment.Recent studies have shown that the biologi-cal clock plays an important role in the development of oral tissues and in the occurrence and treatment of oral diseases.Since there is cur-rently no guiding literature on the research methods of biological clock in stomatology,researchers mainly conduct research based on pub-lished references,which has led to controversy about the research methods of biological clock in stomatology,and there are many confusions about how to rationally apply the research methods of circadia rhythms.In view of this,this expert consensus summarizes the characteristics of the biological clock and analyzes the shortcomings of the current biological clock research in stomatology,and organizes relevant experts to summarize and recommend 10 principles as a reference for the rational implementation of the biological clock in stomatology research.

Objective:To comprehensively analyze the medical resources and services supply in the cancer field of China.Methods:Data of 2018 were sampled from 41 tertiary public cancer hospitals in China, and the factor analysis method was used to extract common factors in resources or services, scoring respectively. Pearson correlation analysis was used in the collinearity test of the variables of both groups of common factors, while the second-order clustering method was used to analyze characteristic differences between the hospitals, and category difference was compared with t test. Results:Resource evaluation covered the two dimensions of basic resources(medical service and basic assurance resources)and high-end resources(high-end talents and academic resources). Service evaluation covered the two dimensions of medical service assurance(clinical services and basic assurance)and disciplinary sphere of influence(discipline construction and clinical efficiency). The factor of basic manpower and beds was significantly correlated with that of medical service and basic assurance( r=0.811, P<0.001), while the factor of high-end talents and academic resources was significantly correlated with that disciplinary construction and resource efficiency( r=0.906, P<0.001). The second-order cluster analysis found the 41 cancer hospitals as two categories, with the first category of five in Guangdong, Shanghai, Beijing and Tianjin, and the second category of the rest 36 hospitals. Significant differences were found between the two categories in terms of resource scoring, service scoring, high-end resources and disciplinary sphere of influence( P<0.001). Meanwhile, the GDP per capita of the cities in which these hospitals are located also had significant differences( P<0.001). Conclusions:Development of public tertiary cancer hospitals in China was imbalanced, as their differences were mainly found in levels of disciplinary development and efficiency of clinical services, which were closely related to the high-end talents and academic resources of the hospital in question.Furthermore, high quality medical care was mostly located in regions of higher development. The authors recommend to take a balanced consideration of the differences and distribution of cancer care services in China, in terms of performance classification of public hospitals and establishment of regional cancer centers of the country.

Cryoablation therapy with explicit anti-tumor mechanisms and histopathological manifestations has a long history.A large number of clinical practice has shown that cryoablation therapy is safe and effective,making it an ideal tumor treatment method in theory.Previously,its efficacy and clinical application were constrained by the limitations of refrigerants and refrigeration equipment.With the development of the new generation of cryoablation equipment represented by argon helium knives,significant progress has been made in refrigeration efficien-cy,ablation range,and precise temperature measurement,greatly promoting the progression of tumor cryoablation technology.This consensus systematically summarizes the mechanism of cryoablation technology,indications for oral mucosal melanoma(OMM)cryotherapy,clinical treatment process,adverse reactions and management,cryotherapy combination therapy,etc.,aiming to provide reference for carrying out the standardized cryoablation therapy of OMM.

Curettage is the main treatment method for oral maxillofacial cystic lesions,but simple curettage may easily damage surrounding structures such as adjacent teeth and nerves,leading to incomplete removal of the cyst and large jaw defects.The curettage assisted by endoscopy can provide a good surgical field for the surgeons,can clearly identify the important anatomical structure during the operation and can remove the cyst wall tissue as much as possible,thereby reducing the damage and reducing the recurrence rate of the lesion.This article combines the characteristics of maxillofacial surgery with clinical treatment experience,summarizes relevant literature from both domestic and international sources,and engages in discussions with experts in order to provide reference for the clinical treatment of jaw cystic lesions with endo-scope assisted curettage.

Neck dissection(ND)is one of the main treatment methods for oral and maxillofacial malignancies.Although ND type is in con-stant improvement,but intraoperative peal-pull-push injury of the accessory nerve,muscle,muscle membrane,fascia and ligament induced shoulder syndrome(SS)is still a common postoperative complication,combined with the influence of radiochemotherapy,not only can cause pain,stiffness,numbness,limited dysfunction of shoulder neck and arm,but also may have serious impact on patient's life quality and phys-ical and mental health.At present,there is still a lack of a systematic evaluation and rehabilitation management program for postoperative SS of oral and maxillofacial malignant tumors.Based on the previous clinical practice and the current available evidence,refer to the relevant lit-erature at home and abroad,the experts in the field of maxillofacial tumor surgery and rehabilitation were invited to discuss,modify and reach a consenusus on the etiology,assessment diagnosis,differential diagnosis,rehabilitation strategy and prevention of SS,in order to provide clinical reference.